Establish a “Yours,” “Mine,” and “Ours” Account

In addition, maintain separate accounts in which each spouse has a little bit of flexible money that they can spend however they like. Mutually agree that each spouse gets to spend this money in whatever way best suits them, and the other partner cannot voice any objection (assuming, of course, that the money is spent on something that’s legal and ethical).

Once the two of you establish this account, both spouses have to hold to the rule that they cannot voice an objection over how the other partner spends his or her money, regardless of how they may feel. In fact, it's best for both spouses not to voice any opinion.

Keep silent about your partner’s purchases the way you would with an acquaintance. This is not your money; it's money that belongs to your spouse, and for the sake of your relationship, you've both agreed to enjoy full autonomy over this portion of your budget.

The two of you need to collaborate when deciding how large your individual accounts should be. Some couples choose to maintain individual accounts that represent incidental amounts of money, such as 1 percent or 2 percent of their overall household budget.

If a couple brings in $5,000 per month combined, for example, and they allocate 2 percent of that income to their individual accounts, they'll each have $50 per month ($100 total) to play with as they like.

Other couples choose to keep a more significant proportion of their household budget in their individual accounts, such as 5 percent, 10 percent, or even 20 percent.

If that same couple that brings in a combined $5,000 per month decides to allocate 20 percent of their income towards this project, then each individual partner gets $500 per month to spend however they’d like. In this example, a total of $1,000 is dedicated towards the “yours and mine” project.

What If You Earn Different Amounts?

This situation gets tricky if you and your spouse earn drastically different amounts of money.

The higher-earning spouse may feel as though he or she is subsidizing the lower-income spouse, particularly if both spouses have income-producing jobs outside of the home, but the higher-earning spouse tends to work longer hours. In some relationships, this can be a source of resentment.

On the other hand, the lower-income spouse can feel under-appreciated, particularly if he or she takes on the majority of household tasks. In these situations, the lower-income spouse may feel as though their domestic contributions are not being recognized.

Some couples allocate an equal amount of money to each person, regardless of each individual’s income.

Some couples allocate money to each person that’s proportional to their respective levels of income. If one partner brings in 70 percent of the combined household income, while the other partner brings in the remaining 30 percent, then each individual gets a personal spending account that's proportional to their financial contribution.

Some couples pay a “salary” to the spouse who handles the majority of household tasks.

As you can see, these represent unique approaches. None of these are better or worse than any other option, they’re just different. Personal finance is “personal,” so you need to decide which approach best fits your values, personalities, and styles.